Overdoped cuprates with high-temperature superconducting transitions

Massimo Marezio (1, 2) , Omar Chmaissem (3) , Catherine Bougerol (4) , M. Karppinen (5) , H. Yamauchi , T. H. Geballe (6)

1 Istituto dei Materiali per Elettronica e Magnetismo del Consiglio Nazionale delle Ricerche
2 CRETA - Consortium de Recherches pour l'Emergence des Technologies Avancées
3 ANL - Argonne National Laboratory [Lemont]
4 NEEL - NPSC - Nanophysique et Semiconducteurs
5 Department of Chemistry,
6 Stanford University

Evidence for high-Tc cuprate superconductivity is found in a region of the phase diagram where non-superconducting Fermi liquid metals are expected. Cu valences estimated independently from both x-ray absorption near-edge spectroscopy and bond valence sum measurements are >2.3, and are in close agreement with each other for structures in the homologous series (Cu0.75Mo0.25)Sr2(Y,Ce)sCu2O5+2s+δ with s = 1, 2, 3, and 4. The record short apical oxygen distance, at odds with current theory, suggests the possibility of a new pairing mechanism. The possibility that the charge reservoir layers are able to screen long range coulomb interactions and thus enhance Tc is discussed.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Massimo Marezio, Omar Chmaissem, Catherine Bougerol, M. Karppinen, H. Yamauchi, et al.. Overdoped cuprates with high-temperature superconducting transitions. APL Materials, 2013, 1 (2), pp.021103. ⟨10.1063/1.4817895⟩. ⟨hal-00856022⟩